Saturday, August 8, 2009

A pixel, from Earth to the Moon

This is a translated version of this post, written originally in Portuguese by Kentaro Mori at 100nexos and translated by Carlos Hotta.

Can you imagine a 1.700 km rock about 400.000 km from Earth? It is really hard for us to picture that. This rock, however, is our Moon. It is really difficult to grasp the Moon's distance and dimensions, specially because our senses fool us. Try to represent with your hands, or even your arms, the size of the Moon in the sky. If you did that, you probably made a circle that is much larger than the one you see in the sky.

The angular size of the Moon is only half of a degree. If you extend your arm in front of you with your thumb pointing up, its width is about two degrees. That is right: if you extend your thumb towards the the Moon, you can cover it about four times. Even thought the Moon is 1.700 km. Go on and check yourself! Almost everyone of us will overestimate the size of the Moon in the sky. Some of us will even use their arms when estimating it! This is called the Moon illusion. And this is why the Moon looks so tiny when we take a picture of it: cameras do not lie but our brains do.

We have been observing the sky above us for thousands and thousands of years. We have understood the celestial mechanics for a few centuries. And four decades ago, humans, with no more than six degrees of separation from you and I, have landed in the Moon. There you could not cover the Moon with your thumbs (unless you put then directly in front of your eyes, an occasion when you would see little else).

There are many ways to express how fantastic it was to land in the Moon. As we are talking about distances, please have a look at the image bellow - the inspiration of this post - and join me towards the infinite --- and beyond.

This image was created by Drew Olbrich, that wanted to correctly represent the scale between sizes and distances of the Earth and the Moon. We are used to see the pair represented in an artistic way, ignoring their true proportion. This is understandable, as you can see the emptiness between both bodies. This is the truth, however, the space is a great emptiness. In order to see this image in space, you would have to be approximately 560.000 km from where you are now. You may click the image to visit Olbritch's site and check the image with higher resolution.

This image has the most impact if you make it fill your whole screen and then turn off all the lights in the room" recommends Olbrich. "Stare at it for a while and try to imagine that you're out in space looking back through some kind of bizarre porthole."

Speaking of higher resolution, while I was contemplating Olbrich's image I started thinking of what would be the size of Apollo space shuttle in the image. It would certainly be so tiny that it would be invisible to us. The next geekiest question would be: what should be the image's minimum resolution to make the modules appear as a single pixel?

Experience the translated post HERE.

No comments: